1990 TGP Dies on the highway. 2am and freeezing.

spyonu2007 · January 09, 2004, 02:39:57 PM

It was a brisk evening, and I needed to fill up so I did so with some good ol 93 octane. I noticed there after that the car started to lope alone abit at part throttle, surging ever so slightly. I figured it was the ecu making since of the cold air and it would work itself out... It didnt. Cruising back on the higway I was maintainign about 75-80, occasionally more than that when the road permitted doing so... I was about to take an off ramp when I noticed that the motor seemed to stall, no power, just dead. It happend after about 4 seconds of wot form 70-90 or so. I pulled of to the side of the road, the car would not start. Checked the fuses for the fuel pump, and the selinoid. Selinoid kicked on & the fuse was fine. I went through the other fuses none of which had tblown. My first thought is the fuel pump died, but I suppose it could be a crank angle sensor. Any thoughts?

idbeast · January 09, 2004, 06:35:50 PM

I've seen it happen with The DIS Module, or the crank sensor. :drinking: :drinking: :bag:

red90TGP · January 10, 2004, 07:21:56 AM

Could it be bad gas?
Just this past September I went and filled up my tank with some 93 octane and drove about 3 miles home. Next day, started it up and only got about 1/4 mile before it quit. To make a long story short, the gas I had gotten was about 1/3 water :x I drained the tank and filled up with some good gas and luckily it was fine.

tyroelite · January 10, 2004, 08:38:34 AM

i say we ban winter from the callendar.... too darn cold... wouldn't have made the engine work anybetter but at least it wouldn't have been so bad to walk or wait for a ride. I feel for ya man. GOOD LUCK

spyonu2007 · January 10, 2004, 04:06:54 PM

Oddly enough after sitting for two days it fired back up and wreaked of fuel as if it was flooded. I am curious how the ecu regulates fuel, I know it has preset maps that follow engine load, throttle position and engine rpm. hypothetically if there was a subtantial boost leak somewhere could the car flood at wot? Saying that it is only reading the maps based off the TPS and engine RPM. One would think that it would also look at the mas air meter. Anyway I am going to look for boost leaks and such and keep an eye on it. Runs great again, fuel pressure was good. Ill keep ya all informed on what I find.

god910 · January 11, 2004, 09:52:49 AM

Our cars are MAP based so, no mass air. The tables for fuel are 3D, MAP, RPM, and load. So, if you had a leak, it would see low, or NO, manifold pressure, and adjust the fuel just as if you were N/A. Trust me, I had a I/C pipe pop off on a WOT run. The car didn't miss a beat, it just put my head into the windshield. :lol: And then ran just fine. (Like a slow ass 5 speed N/A Grand Prix) :evil:

Jeff M · January 11, 2004, 08:23:41 PM

Do a simple test, pull off the vacuum line at the Fuel Pressure Regulator/FPR and attach another vacuum line and suck on it, do this when the engine is fully warm too, if it does not hold a vacuum, that is a problem! (replace it of course). Last is the fuel injectors (do a search for tons of info I posted on this once, but anyways), ohms might be dropping on a few which will overload the injector drivers in the ECM, causing it to shut down till it cools (meaning you can pop the hood, open the ECM cover area to allow the ECM to cool enough to get you back on your way, for a while), but your rich fuel sounds more like the FPR starting to act up when hot, in time will do this even cold. Possible ignition as was said and good to check those out as well, but FPR is an easy one to check and these fueling issues are more common.

Good luck!

spyonu2007 · January 11, 2004, 11:10:15 PM

Thanks for all the responses, I had three rather large boost leaks at the intercooler piping, and near the intake manifold. Two clamps were loose and another was plain broke. Its always nice when its an easy fix.

Jeff M · January 11, 2004, 11:25:29 PM

I wish that was it for you :( but leaks in the intake pipes/turbo pipes/intercooler pipes will not cause you to stall, and have a no-start condition. A leak in those area will only give you a lack of power when trying to boost (and some interesting hissing)!
Keep looking as suggested above, let us know what you find, good to hear back again what is the common tricks taking care of the cars 8) .

Jeff M

spyonu2007 · January 18, 2004, 03:37:54 PM

So it is impossible to flood the car out with the stock fuel maps at wot with no boost? I will check the rest of the listed for possible failures.

god910 · January 19, 2004, 07:23:02 PM

I have driven my car about 10 miles through the city one day (WOT, and all other throttle positions) never had any problems. Your fuel is RPM, TPS, and MAP based (3D) Without a high MAP reading it won't add fuel to accomodate... No boost, no added fuel.

spyonu2007 · January 23, 2004, 05:59:23 PM

Jeff: ohms might be dropping on a few which will overload the injector drivers in the ECM, causing it to shut down till it cools (meaning you can pop the hood, open the ECM cover area to allow the ECM to cool enough to get you back on your way, for a while).

Intersting. I did some checking and the dealership has put in 2 sets of injectors in the last couple of years for the same issue. (wasnt mentioned to me when I got the car, but now I am aware.

The ecu has evidently been replaced with a refurbished one...

The plot thickens, perhaps it is a blessing in disguise, the winning bidder on my auctino hasnt returne my emails. Probably a good thing seeing that it is not running right.

FPR tested good. Holds -25psi of vacume.

Bacically what is happening when lookikng at the driver lines form the ecu that activate the injectors, on the non start condiition the trouble lite illuminates very dim, (coming from the ecu). Wait a hour or two and bam it fires right up and runs right up until you press the throtte a quarter of the way. Car dies and wont start. Injectors are not oppertaing. (all off them).,

The circuit that looks at impedance in the ecu may be shot I suppose. Any thoughts? I have spark, great fuel pressues (48psi)... Is the injector driver assembly a serviceable unit?

Jeff M · January 26, 2004, 08:13:17 AM

Sorry, got no email telling me there were more replies, mainly yours!!! Ohh a fun one eh, I live for these. With the good info/reply you gave about the dim trouble light tested in-line to the injector feed, check the grounds for the puter, 2 sets down back by the knock sensor, under the alternator area, 2 Tan Wires into one ring spade and 2 Black Wires in the other ring spade, if good then check the main grounds at the engine block, below the turbo and to the left looking at the engine, quite a few there under a nut over a stud that bolts the trans case to the engine block, greasy area but that is good at warding off corrosion! If not then find someone with a working 727 puter or 128 or 260 last 3 digit version swap it in. Last possibility is wrong injectors, happens so don?t discount it, had a guy I spent tons of hours on emails and the phone un-fixing prior fixes till we found (among other things) Standard brand injectors (Standard and Blue Streak are company names) are very wrong for the TGP, the book says for the TGP but are the wrong injectors and I mean wrong as in 14 pound units (as I recall, glad to forget that job!). If you had a scan tool you would see very high BLM and INT values showing the computer adding tons of fuel to make up for these tiny injectors, and a stall when increasing engine speed follow this same thought. There are only a few literate guys who can explain the parts in our ECMs to allow chip replacements such as drivers, (lots of custom numbers in there). Standard are all black units if I recall correctly, Multecs are dull silver over black, you can see a few enough to tell. Possible loose connections at the ECM, maybe a bad pin, but check these other items first and let us know what you find, and I will try and check back here, its hard as I am working another 40 hour day and I am getting too old (almost as old as Jim :lol: ) to keep doing this :crazyeyes: .

Jeff M

spyonu2007 · February 15, 2004, 01:06:59 AM

well, all of the grounds have been checked. The shop where my car is sitting is owned by a couple of friends that I trust, though this is the first grandprix they have encountered. Be that is it may, they swapped a non turbo computer into the car and it ran breifly and now once agaon ot doesnt run.

I guess I am looking for a turbo computer, if anyone has a lead on one to borrow for a few day let me know. 309-645-5618. I wish I had the time to be more hands on with this, but right now it seems the only info I feed them is the only info they are getting.

Side note the crossover pipe came out perfect... Now if I could jsut get her to run. I am going to check the impedance on the injectors, not sure if they have done that yet. Anyway its late, Im still recovering from the stamina draining effects that Valentines day enduces on married folk.

Thanks for all the data, everyone.

TGPRobNY · February 16, 2004, 07:58:31 AM

As long as the service code is the same...it can come from a non turbo car. The turbo difference is in the chip itself which has to be switched. I picked up a non turbo 'puter and switched the chip and it works fine.